Such a method for operating a drive mechanism provided for shifting an automatic transmission is known from DE 103 16 442 A1. The drive mechanism has a brushless electric motor, which shifts a mobile element of the transmission. In order to position the mobile element, the winding of the electric motor is addressed via a control electronic. The rotation of the mobile element is measured by an incremental rotation measurement signal being determined using reverb sensors. The rotation measurement signal is also used to absolutely determine the position of the mobile element. Using the engine, the mobile element is first brought into a known predetermined position. Subsequently, an absolute position signal is set to a reference value allocated to a reference position. Then the mobile element is displaced out of the reference position in order to select a gear requested by the transmission control. The incremental rotation measurement signal is controlled here, in order to follow the absolute position signal with each change of the incremental position measurement signal. During the positioning process of the mobile element the rotation measurement signal is compared to saved rotation signals. If any deviation is determined, a neutral reference shift is initiated. This largely avoids mistakes even during the shifting of the transmission, which might lead to a critical driving condition, damage to the transmission, and/or a dangerous situation when, due to a malfunction, too many or too few increments were measured in the rotation measurement signal. However, by this reasoning an erroneous positioning of the mobile element cannot be detected or avoided in all cases, in particular, when only few increments were missed or counted in excess and the error remains within the range of the mechanical tolerances and the statistic variations of the measurements.